why is it intended for arms and legs of the parched to not be mirrored while every other skeleton and variant types arms and legs are mirrored
Curently this issue can be worked around by using commands on the placed block such as "/data modify block ~ ~-1 ~ normal_config.spawn_potentials set value [{data:{entity:{id:"minecraft:spider"}},weight:1}]". this bug is spawn egg specific
have the same problem with 1.10-pre-1, 1.10-pre-2 and the official 1.10 version.
this bug makes it very very hard for resourcepack creators to make retextures for the parched since the leg overlays are bugged. i do hope this issue will get looked at in the future